The average person may not associate coolness with the sun. The sun releases energy through deep nuclear fusion reactions in its core and has surface temperatures as hot as 10,000 degrees Fahrenheit, according to NASA’s Web site.

Not cool at all. But the sun’s recent activity, or lack thereof, may be linked to the pleasant summer temperatures the midwest has enjoyed this year, said Charlie Perry, a research hydrologist with the U.S. Geological Survey in Lawrence. The sun is at a low point of a deep solar minimum in which there are little to no sunspots on its surface. In July through August, 51 consecutive days passed without a spot, one day short of tying the record of 52 days from the early 1900s.

As of Sept. 15, the current solar minimum ranks third all-time in the amount of spotless days with 717 since 2004. There have been 206 spotless days in 2009, which is 14th all-time. But there are still more than 100 days left in the year, and Perry expects that number to climb. Perry, who studies sunspots and solar activity in his spare time, received an undergraduate degree in physics at Kansas State University and a Ph.D in physics and astronomy at The University of Kansas. He also has spent time as a meteorologist.